Plates allowing adjustment of caster and camber

ABSTRACT

An apparatus allows for the independent adjustment of caster and camber for vehicles utilizing MacPherson strut front suspensions. The apparatus has, in stacked arrangement, a fastener plate, a lower plate, and an upper plate. Camber adjustments are generally made by manipulation of the lower plate and caster adjustments are generally made by manipulation of the upper plate. The upper plate may be mounted in two different positions to allow for different camber adjustments, such as for competitive situations and non-competitive situations. The device utilizes a thrust bearing having a race in the upper face of the spring perch and an opposing race which mounts around the base of the bearing cup.

BACKGROUND OF THE INVENTION

The present invention relates generally to automobile suspension systemsand more particularly to devices which provide for the independentadjustment of camber and caster. Some automobiles, such as Ford Mustangsdating from 2005 to the present, hereinafter collectively referred to as“2005+ Mustangs”, are equipped from the factory with MacPherson strutfront suspensions. The camber and caster angles for the MacPherson strutsuspensions found in the 2005+ Mustangs are fixed at the factory to aset position which reduces maintenance. The MacPherson strutconfiguration utilized in the 2005+ Mustangs have a strut rod at the topof the strut which mounts to a plate or other attachment assembly withina strut tower of the chassis as known in the art. The OEM upper strutmounting assemblies on these vehicles typically do not allow for camberor caster adjustments, although some vehicles may have mechanisms whichallow for camber adjustment, such as slots in the strut tower whichallow some camber adjustment.

However, while the fixed camber and caster settings may provideperformance which is generally satisfactory for every day commutingpurposes, the fixed settings do not provide the performance sought byautomotive enthusiasts who desire to use their vehicles in competitiveevents such as road rallies, road racing, drag racing, etc. These usersprefer to have precise control of the handling of their vehicles for theparticular application. For example, in road racing, negative camber,where the bottom of the wheel is further out than the top of the wheel,is desirable because it improves tire grip when cornering. However, indrag racing, where maximum straight-line acceleration is desired, thegreatest traction is obtained where the wheel has no camber angle andthe tire tread is flat on the road.

Moreover, competitive owners frequently lower their vehicles to improveperformance, which puts the camber out of the factory specification,which can increase wear on the tires and have a negative impact onhandling.

It is also desirable to be to adjust the caster angle, which is theangular displacement between a vertical axis and the pivot line (animaginary line running through the center of the upper ball joint to thecenter of the lower ball joint. Improper caster settings make it moredifficult to maintain a straight line and can make steering heavier andless responsive. Caster adjustments may correct steering problems, suchas causing the vehicle to pull toward the side with less positivecaster. Positive caster improves the vehicle's straight line stability,which is a desired quality for drag racing.

Thus, it is desirable to have an apparatus which may be installed toreplace the original manufacturer's parts, where the apparatus allowsthe adjustment of camber and caster in vehicles, such as 2005 and laterFord Mustangs, and other vehicles which have factory pre-set andnon-adjustable caster and camber settings

SUMMARY OF THE INVENTION

Embodiments of the method and apparatus disclosed herein provide asolution to the problem described above. For purposes of this disclosureand the claims herein, the terms “front” and “back” (or “forward” and“rearward”) respectively indicate directions which are toward the frontand back of the vehicle. Likewise, the terms “up” and “down” (or“upward” and “downward”) respectively indicate directions which aretoward the ground and toward the top of the vehicle.

Embodiments of the apparatus for adjusting caster and camber may begenerally summarized according the following description. The apparatushas, in stacked arrangement, a fastener plate, a lower plate, and anupper plate. Camber adjustments are generally made by manipulation ofthe lower plate and caster adjustments are generally made bymanipulation of the upper plate.

At least one fastener plate is utilized to secure the position of a coilspring-strut assembly of a MacPherson-syle front suspension assembly.The different plates of the device are used to adjust camber and caster.The fastener plate (or fastener plates) has a plurality of threadedfastening members, typically threaded studs attached or inserted throughthe fastener plate, where the fastening members extend upwardly from anupwardly facing of the fastener plate. These fastening members attach toa portion of the vehicle chassis known as the strut tower. Typically,the fastening members extend through openings at the top of the struttower, where nuts are made up onto the threads of upwardly extendingfastening members. If a single fastener plate is utilized, the interiorof the fastener plate has a cutout portion defined by an interior wall.If more than one fastener plate is used, the positions of the installedmultiple fastener plates define a cutout portion.

Disposed in general overlaying relation to the fastener plate is thelower plate. The lower plate has a downwardly facing bottom sidepositioned adjacent to the upwardly facing face of the fastener plate.The threaded fastening members extend through openings in the lowerplate. The lower plate has a bearing cup, referred to herein as theshaft housing, which substantially depends from the downwardly bottomside, but may also have a portion extending above the upwardly top sideof the lower plate. The shaft housing is typically a cylindricalstructure with an opening extending throughout its length. The shafthousing extends through the interior cut-out portion of the fastenerplate. The bore of the shaft housing is for receiving an end of a strutshaft therethrough, along with bearing or bushing components which mountwithin the shaft housing and allow rotation of the shaft housing. Thelower plate is releasably adjustable with respect to the fastener platealong a first axis, hereinafter referred to as the “X” axis, and along asecond axis, hereinafter referred to as the “Y” axis. The X axis and theY axis are substantially non-parallel and may be perpendicular to oneanother.

Disposed in general overlaying relation to the lower plate is the upperplate. The upper plate has a downwardly facing bottom side positionedadjacent to a top face of the lower adjustment plate. The upper platehas openings which sufficiently align with the openings in the lowerplate to allow the threaded fastening members to extend through theopenings in the upper plate. The interior of the upper plate has acutout portion defined by an interior wall, which allows for any portionof the shaft housing which extends above the top side of the lower plateto move within the cutout portion. The upper adjustment plate and thelower adjustment plate are jointly configured for allowing relativemovement between the two plates along the X axis but restrictingmovement along the Y axis.

The upper plate has a plurality of protruding members depending from thedownwardly facing bottom side which are each received within acorresponding elliptical aperture in the lower plate. The engagement ofthe protruding members with the corresponding elliptical aperturesallows relative movement between the upper plate and the lower platealong the X axis while inhibiting relative movement between the upperplate and the lower plate along the Y axis. A thrust bearing assemblycouples to the lower plate. The thrust bearing assembly may have anupper member having an upper race, a spring perch comprising a lowerrace, and plurality of ball bearings disposed between the upper race andthe lower race. The upper member and the spring perch have openings forreceiving the shaft housing which couple the spring perch, and thereforethe thrust bearing assembly to the lower plate. The spring perchprovides a seat for the upper end of the coil spring which is acomponent of a MacPherson strut suspension.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an embodiment of the apparatus mounted on a strut shaft.

FIG. 2 shows an embodiment of the apparatus for adjusting caster andcamber, viewed from the bottom, as mounted within a strut tower.

FIG. 3 shows an exploded view of an embodiment of the apparatus.

FIG. 4 shows an exploded view of an alternative embodiment of theapparatus, with the thrust bearing in an assembled configuration.

FIG. 5 shows a bottom view of an embodiment of the apparatus showingdetail of a portion of the thrust bearing.

FIG. 6 shows the components of an embodiment of the thrust bearingassembly.

FIG. 6A shows a sectioned view of the thrust bearing assembly of FIG. 6.

FIG. 6B shows a detailed view of the sectioned view of FIG. 6A.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring specifically to the figures, FIG. 1 shows a perspective viewof an embodiment of the disclosed camber/caster adjustment plateapparatus 10 (hereinafter, “apparatus”). As shown in FIG. 1, theapparatus is in a stacked configuration having an upper plate 12, alower plate 14, and a fastener plate 16. A strut shaft 18 from aMacPherson strut (not shown) extends through a shaft housing 20 and isretained within bearing assembly 22. As shown in FIG. 2, the adjustmentplate apparatus 10 is fastened to an upper surface 24 of strut tower 26.Referring to FIGS. 1 and 2, once caster and camber are adjusted asdesired, the adjustment plate apparatus is fastened to the upper surface24 by fastening members 28 which are secured to the upper surface 24 ofstrut tower 26 by nuts 30 and washers 32, and by either inserting a bolt(not shown) into either one of the threaded apertures 42 or nuts 42′,which may be pressed-in and/or depend from lower face 50 or by placing anut on fastener 42″ The upper plate may comprise a forward side 51, arearward side 53, a left side 55 and a right side 57.

Fastening members 28 extend through elliptical apertures 29 in lowerplate 14 where the elliptical apertures have a long axis generallyparallel to the X axis. The positioning of fastening members 28 alongthe X axis within the elliptical apertures 29 in the lower plate 14generally allows for making camber adjustments. It is to be noted thatelliptical apertures 29 are wide enough to allow some motion of thestacked adjustment plates in the direction of the Y axis for adjustingcaster Fastening members 28 extend through elliptical apertures 31 inupper plate 12 (or 12′), which have a long axis generally parallel tothe Y axis. The positioning of fastening members 28 along the Y axiswithin the elliptical apertures 31 in the upper plate generally allowfor making caster adjustments.

Fastening members 28 are attached through, attached to, or integral tofastener plate 16. As shown best in FIGS. 3-4, fastener plate 16 has aninterior cut-out portion 34, which is bounded by an interior peripheralwall 36. Similarly, upper plate 12 has an interior cut-out portion 38which is bounded by an interior peripheral wall 40. Interior cut-outportions 34 and 38 are generally elliptical in shape and allow movementof the plates and the shaft housing 20 prior to the tightening of nuts30 on fastening members 28.

In addition to being fastened to the upper surface 24 by fasteningmembers 28, upper plate 12 comprises either a threaded aperture 42, apressed-in nut 42′, or an integral fastener 42″, any of which aredisposed within an extending tab 44 which extends outside of the sides46 of lower plate 14. Any one of the threaded aperture 42, thepressed-in nut 42′ or the integral fastener 42″ of extending tab 44 areutilized to secure upper plate 12 to the upper surface 24 of strut tower26. This feature allows the upper plate 12, which is manipulated toadjust caster, to be secured, while still allowing manipulation of lowerplate 14 in the direction of the X axis so that camber adjustment, whichis made by manipulation of the lower plate 14 along the X axis, may beaccomplished independent of the caster setting.

Upper plate 12 may comprise a single extending tab 44, or may have anextending tab 44 on either side of the upper plate. The extending tabsmay either on the left side 55 or the right side 57, or on both sides ofupper plate 12. As shown best in FIG. 2, the tabs 44 may be offset fromone another, such that, with reference to the X axis, one tab is at adifferent position than the second. This offset may be utilized toprovide different camber settings according to which setting isutilized. For example, the offset may be utilized to generally set afirst camber setting utilized for competition purposes and a secondcamber setting utilized for non-competition purposes. The desired cambersetting can then be realized by rotating the upper plate 12 by 180degrees to select the desired tab and aligning the selected tab with anaperture in the upper surface 24 of the strut tower 26 and either makingup a bolt into the threaded aperture 42, pressed-in nut 42′, or placinga nut on integral fastener 42′.

In order for camber and caster to be set independently from one another,it is necessary that lower plate 14 may be moved relative to upper plate12 along the X axis after the camber adjustment has been fixed bysecuring upper plate 12 to the upper surface 24 of the strut tower 26 asdescribed above. However, once upper plate 12 has been secured to theupper surface 24 of the strut tower 26, further movement of lower plate14 along the Y axis is inhibited by an interlocking structure betweenthe two plates. This interlocking structure generally comprises theengagement of a plurality of protruding members 48 which depend from thelower face 50 of the upper plate 12 (or 12′), where each protrudingmember is received within an elliptical aperture 52 corresponding toeach of the protruding members. The protruding members 48 have adiameter which is sufficiently small to fit within elliptical apertures52, but which is large enough to inhibit or restrict any appreciablemotion along the Y axis. However, elliptical apertures 52 aresufficiently long to allow for approximately one inch of motion alongthe X axis. Protruding members 48 may be pins attached to lower face 50,or may be installed through apertures in upper plate 12, or upper plate12 may be machined such that the protruding members are machined fromthe fabrication material and the protruding members are integral postsmachined into upper plate 12.

Fastener plate 16 may be generally, but not necessarily, rectangular,having a left side 59, a right side 61, a forward side 63, and arearward side 65. Either the left side 59 and/or the right side 61 mayhave a cut-out portion 60, 62. The cut-out portions 60, 62 are adaptedto receive an edge of pressed-in nuts 42. Likewise, the interiorperipheral wall 36 which defines interior cut-out portion 34 of fastenerplate 16 may have semi-circular apertures 64, 66 which may receive theedges of the protruding members 48 depending from the lower face 50 ofupper plate 12. The engagement of the edges of the pressed-in nuts 42into cut-out portions 60, 42 and the engagement of the edges of theprotruding members 48 into semi-circular apertures 64, 66 serve to lockupper plate 12 to lower plate 16.

Embodiments of the device may comprise a thrust bearing assembly 100which comprising an upper member 102 having an upper race 104, a springperch 106 comprising a lower race 108, and plurality of ball bearings110 disposed between the upper race and the lower race. Upper member 102and spring perch 106 may each have an hemi-spherical or ellipticalgroove 112, 114 in the opposing faces of each which may be utilized fordisposing O-ring 116. The upper member 102 and spring perch 106 eachhave axially-aligned openings 118, 120 for receiving the shaft housingthereby coupling the spring perch to the lower plate.

With the various nuts and fasteners holding the apparatus in place in aloosened state, the lower plate 14 and the upper plate 12 may bepositioned along the X axis and the Y axis. Caster may be adjusted bymanipulating the coil spring-strut assembly and then locking the upperplate 12 into position by attaching the upper plate to the upper surface24 of strut tower 26 by insertion and tightening of a fastener intothreaded aperture 42 or pressed-in nut 42′ or tightening a nut onintegral stud 42″.

Once caster is set, the coil spring-strut assembly may be manipulated toadjust camber, and nuts 30 tightened on threaded fasteners 28 to lockthe camber adjustment into position. As discussed above, a preliminarycamber setting may be realized by selecting whether to attach a fastenerto either the left side 55 or right side 57 of upper plate 12, becausethe attachment points (e.g., threaded aperture 42) on the left side andthe right side may be offset with respect to the X axis. For example,the threaded aperture on the left side 55 may have a center which ishalf-an inch forward of the center of the threaded aperture on the rightside 57.

While the above is a description of various embodiments of the presentinvention, further modifications may be employed without departing fromthe spirit and scope of the present invention. Thus the scope of theinvention should not be limited according to these factors, butaccording to the following appended claims.

What is claimed is:
 1. An apparatus for adjusting caster and camber, theapparatus comprising: at least one fastener plate comprising a pluralityof threaded fastening members extending from a first face of thefastener plate for attachment to a vehicle strut tower; a lower platehaving a lower face thereof positioned adjacent the first face of thefastener plate with the threaded fastening members extending through thelower plate, the lower plate comprising a shaft housing depending fromthe lower face, the shaft housing having a bore configured for receivingan end of a strut shaft therethrough, wherein the lower plate isreleasably adjustable with respect to the fastener plate along a firstaxis and a second axis, wherein the second axis is substantiallynon-parallel to the first axis; an upper plate having a lower facepositioned adjacent to a top face of the lower plate such that saidthreaded fastening members extend therethrough, wherein the upper plateand the lower plate are jointly configured for allowing the upper plateto be releasably adjustable with respect to the fastener plate along thesecond axis; wherein the upper plate comprises a plurality of protrudingmembers depending from the lower face of the upper plate; wherein thelower plate comprises a plurality of elliptical apertures, an ellipticalaperture of the plurality of elliptical apertures corresponding to andreceiving one of each of said plurality of protruding members, whereinthe receiving one of each of said plurality of the protruding memberswith the corresponding elliptical apertures of the plurality ofelliptical apertures allows relative movement between the upper plateand the lower plate along the first axis while inhibiting relativemovement between the upper plate and the lower plate along the secondaxis.
 2. The apparatus of claim 1 further comprising a thrust bearingassembly comprising an upper member having an upper race, a spring perchcomprising a lower race, and plurality of ball bearings disposed betweenthe upper race and the lower race, wherein the upper member and springperch comprise openings for receiving the shaft housing thereby couplingthe spring perch to the lower plate.
 3. The apparatus of claim 1 whereinthe protruding members comprise pins attached to the upper plate.
 4. Theapparatus of claim 1 wherein the protruding members comprise integralposts.
 5. The apparatus of claim 1 wherein the upper plate comprisesfour sides.
 6. The apparatus of claim 5 wherein the four sides comprisea forward side, a rearward side, a left side, and a right side.
 7. Theapparatus of claim 6 wherein either the left side or the right sidecomprise an outwardly extending tab integral to the upper plate, the tabcomprising an aperture extending through the tab member.
 8. Theapparatus of claim 6 wherein both the left side and the right sidecomprise an outwardly extending tab integral to the top plate, the tabseach comprising an aperture extending therethrough.
 9. The apparatus ofclaim 7 wherein the aperture comprises a threaded nut disposed withinthe aperture.
 10. The apparatus of claim 8 wherein the aperturescomprise threaded nuts disposed within the apertures.
 11. The apparatusof claim 7 wherein the aperture comprises threads.
 12. The apparatus ofclaim 1 wherein the fastener plate comprises an interior cutout portiondefined by an interior peripheral wall and the interior peripheral wallcomprises semi-circular apertures for receiving a portion of theprotruding members depending from the lower face of the upper plate. 13.The apparatus of claim 10 wherein the fastener plate comprises a leftside and a right side and the left side and the right side each comprisea cutout portion adapted to receive an edge of the threaded nuts. 14.The apparatus of claim 8 wherein the extending tab of the left side andthe extending tab of the right side are offset from one another.
 15. Anapparatus for adjusting caster and camber, the apparatus comprising: afastener plate comprising four upwardly extending threaded fasteningmembers extending from a top face of the fastener plate for attachmentto a vehicle strut tower, the fastener plate comprising an interiorcut-out portion defined by an interior peripheral wall of the fastenerplate; a lower plate having a lower face thereof positioned adjacent thetop face of the fastener plate with the threaded fastening membersextending through four elongated apertures in the lower plate, the lowerplate comprising a first side and a second side, the lower platecomprising a shaft housing depending from the lower face and extendingthrough the interior cut-out portion of the fastener plate, the shafthousing having a bore configured for receiving an end of a strut shafttherethrough, wherein the lower plate is releasably adjustable withrespect to the fastener plate along a first axis and a second axis,wherein the second axis is substantially perpendicular to the first axisand the four elongated apertures are substantially parallel with thefirst axis; an upper plate having a forward side, a rearward side, aleft side and a right side, wherein both the left side and the rightside comprise an outwardly extending tab integral to the upper plate,the tabs each comprising an aperture extending therethrough, saidapertures respectively extending outward of the first side and thesecond side of the lower plate, the upper plate further comprising alower face positioned adjacent to the top side of the lower plate suchthat said threaded fastening members extend therethrough, wherein theupper plate and the lower plate are jointly configured for allowing theupper plate to be moveable with respect to the fastener plate along thesecond axis; wherein the upper plate further comprises a pair ofprotruding members depending from the top face of the upper plate; andwherein the lower plate comprises a pair of elliptical apertures, anelliptical aperture corresponding to and receiving one of each, whereinthe engagement of the protruding members with the correspondingelliptical apertures allows relative movement between the upper plateand the lower plate along the first axis while inhibiting relativemovement between the upper plate and the lower plate along the secondaxis.
 16. The apparatus of claim 15 wherein the apertures in theoutwardly extending tabs each comprise threaded nuts disposed within theapertures in the outwardly extending tabs.
 17. The apparatus of claim 16wherein the fastener plate comprises a left external side and a rightexternal side and the left external side and the right external sideeach comprise a cutout adapted to receive an edge of a corresponding nutin the upper plate.
 18. The apparatus of claim 15 wherein the extendingtab of the left side and the extending tab of the right side are offsetfrom one another.
 19. The apparatus of claim 15 wherein the protrudingmembers comprise pins attached to the upper plate.
 20. The apparatus ofclaim 15 wherein the protruding members comprise integral posts.